I have always wondered why I have this phobia because it even sounds
weird to me. I can't imagine a genetic predisposition for it but I
can't think of any environmental causes for mine either. I was
wondering if we all have something in common that might give some
clue. Here is a basic list that I am curious about:

Sex: Male/Female
Where you grew up:
Current Age:
Age when you first remember having this fear:
Education level:
Parents Education level:
Parent's marital status:
Number of siblings:
Your placement in that number:
Social economical status growing up:
Traumatic events before your first memory of this:
Other phobias:
Other family members with this phobia:
Other family members with other phobias:

I am sure there is a bunch more and better questions so feel free to
add to them.

Here are my answers
Sex: Male
Where you grew up: Northern Michigan (USA)
Current Age:41
Age when you first remember having this fear: about 8
Education level: Masters in Computer Science
Parents Education level: Dad- BS in Mechanical Eng. and MBA. Mom:
Bachelors in Home Economics
Parent's marital status: Married for 45 years
Number of siblings: 2 brothers 1 sister
Your placement in that number: 3rd child, middle boy
Social economical status growing up: Upper Middle Class
Traumatic events: None that I can think of.
Other phobias: pearls, some jewelry
Other family members with this phobia: None known
Other family members with other phobias: None known